<!DOCTYPE html>
<html>
<head>
  <title>Invalidation of iterators over XPath results</title>
  <link rel="author" title="Simon Wülker" href="mailto:simon.wuelker@arcor.de">
  <link rel="help" href="https://www.w3.org/TR/DOM-Level-3-XPath/xpath.html#XPathResult-iterateNext">
  <script src="../resources/testharness.js"></script>
  <script src="../resources/testharnessreport.js"></script>
</head>
<body>
  <ul id="list">
      <li id="first-child"></li>
      <li id="second-child"></li>
  </ul>
  <script>
    function make_xpath_query(result_type) {
      return document.evaluate(
        "//li",
        document,
        null,
        result_type,
        null
      );
    }

    function invalidate_iterator(test) {
      let new_element = document.createElement("li");
      document.getElementById("list").appendChild(new_element);
      test.add_cleanup(() => {
        new_element.remove();
      })
    }

    test((t) => {
      let iterator = make_xpath_query(XPathResult.ORDERED_NODE_ITERATOR_TYPE);

      assert_equals(iterator.iterateNext(), document.getElementById("first-child"));
      assert_equals(iterator.iterateNext(), document.getElementById("second-child"));
      assert_equals(iterator.iterateNext(), null);
      assert_false(iterator.invalidIteratorState);
    }, "Using an ordered iterator without modifying the dom should yield the expected elements in correct order without errors.");

    test((t) => {
      let iterator = make_xpath_query(XPathResult.UNORDERED_NODE_ITERATOR_TYPE);

      assert_not_equals(iterator.iterateNext(), null);
      assert_not_equals(iterator.iterateNext(), null);
      assert_equals(iterator.iterateNext(), null);
      assert_false(iterator.invalidIteratorState);
    }, "Using an unordered iterator without modifying the dom should yield the correct number of elements without errors.");

    test((t) => {
      let non_iterator_query = make_xpath_query(XPathResult.BOOLEAN_TYPE);

      assert_false(non_iterator_query.invalidIteratorState);
      invalidate_iterator(t);
      assert_false(non_iterator_query.invalidIteratorState);
    }, "invalidIteratorState should be false for non-iterable results.");

    test((t) => {
      let non_iterator_query = make_xpath_query(XPathResult.BOOLEAN_TYPE);

      assert_throws_js(TypeError, () => non_iterator_query.iterateNext());
    }, "Calling iterateNext on a non-iterable XPathResult should throw a TypeError.");

    test((t) => {
      let non_iterator_query = make_xpath_query(XPathResult.BOOLEAN_TYPE);
      invalidate_iterator(t);
      assert_throws_js(TypeError, () => non_iterator_query.iterateNext());
    }, "Calling iterateNext on a non-iterable XPathResult after modifying the DOM should throw a TypeError.");

    test((t) => {
        let iterator = make_xpath_query(XPathResult.ORDERED_NODE_ITERATOR_TYPE);

        iterator.iterateNext();

        invalidate_iterator(t);

        assert_throws_dom(
          "InvalidStateError",
          () => iterator.iterateNext(),
        );
    }, "Calling iterateNext after having modified the DOM should throw an exception.");

    test((t) => {
        let iterator = make_xpath_query(XPathResult.ORDERED_NODE_ITERATOR_TYPE);

        iterator.iterateNext();
        iterator.iterateNext();

        invalidate_iterator(t);

        assert_throws_dom(
          "InvalidStateError",
          () => iterator.iterateNext(),
        );
    }, "Calling iterateNext after having modified the DOM should throw an exception even if the iterator is exhausted.");
  </script>
</body>
</html>
